Extract date from inside a string with Python

Question

I have the following string, while the first letters can differ and can also be sometimes two, sometimes three or four.

PR191030.213101.ABD

I want to extract the 191030 and convert that to a valid date.

filename_without_ending.split(".")[0][-6:]

PZA191030_392001_USB

Sometimes it looks liket his

This solution is not valid since this is also might differ from time to time. The only REAL pattern is really the first six numbers.

How do I do this?

Thank you!

With the rules you gave it works every time no? Get you give us a counter example when it doesn't work? — Clément
– Clément, Commented Nov 13, 2019 at 10:34

The fourth bird · Accepted Answer · 2019-11-13 10:41:43Z

3

You could get the first 6 digits using a pattern an a capturing group

^[A-Z]{2,4}(\d{6})\.

^ Start of string
[A-Z]{2,4} Match 2, 3 or 4 uppercase chars
( Capture group 1
- \d{6} Match 6 digits
)\. Close group and match trailing dot

Regex demo | Python demo

For example

import re

regex = r"^[A-Z]{2,4}(\d{6})\."
test_str = "PR191030.213101.ABD"
matches = re.search(regex, test_str)

if matches:
    print(matches.group(1))

Output

answered Nov 13, 2019 at 10:41

The fourth bird

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2 Comments

Data Mastery Over a year ago

thank you, really advanced solution. Hope its ok when you accept the one with the list comprehension since I feel more comfortable using that ;-)

The fourth bird Over a year ago

@DataMastery Of course, no problem at all. You should select the solution that works for you. Good luck!

Aryerez · Accepted Answer · 2019-11-13 10:35:40Z

3

You can do:

a = 'PR191030.213101.ABD'
int(''.join([c for c in a if c.isdigit()][:6]))

Output:

answered Nov 13, 2019 at 10:35

Aryerez

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Comments

Maximilian Schaller · Accepted Answer · 2019-11-13 10:41:18Z

1

This can also be done by:

filename_without_ending.split(".")[0][2::]

This splits the string from the 3rd letter to the end.

answered Nov 13, 2019 at 10:41

Maximilian Schaller

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Comments

Community · Accepted Answer · 2020-06-20 09:12:55Z

0

Since first letters can differ we have to ignore alphabets and extract digits.

So using re module (for regular expressions) apply regex pattern on string. It will give matching pattern out of string.

'\d' is used to match [0-9]digits and + operator used for matching 1 digit atleast(1/more).

findall() will find all the occurences of matching pattern in a given string while #search() is used to find matching 1st occurence only.

import re

str="PR191030.213101.ABD"

print(re.findall(r"\d+",str)[0])

print(re.search(r"\d+",str).group())

edited Jun 20, 2020 at 9:12

CommunityBot

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answered Nov 13, 2019 at 11:09

SRG

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Extract date from inside a string with Python

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Since first letters can differ we have to ignore alphabets and extract digits.

So using re module (for regular expressions) apply regex pattern on string. It will give matching pattern out of string.

'\d' is used to match [0-9]digits and + operator used for matching 1 digit atleast(1/more).

findall() will find all the occurences of matching pattern in a given string while #search() is used to find matching 1st occurence only.

Comments

Your Answer

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Collectives™ on Stack Overflow

4 Answers 4

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Since first letters can differ we have to ignore alphabets and extract digits.

So using re module (for regular expressions) apply regex pattern on string. It will give matching pattern out of string.

'\d' is used to match [0-9]digits and + operator used for matching 1 digit atleast(1/more).

findall() will find all the occurences of matching pattern in a given string while #search() is used to find matching 1st occurence only.

Comments

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